摘要
目的:观察切应力对高糖培养的肾近端小管上皮细胞纤溶酶原激活物(tPA)和其抑制物(PAI-1)mRNA表达及对细胞骨架肌动蛋白表达的影响,探讨糖尿病肾病(DN)早期高滤过致肾近端小管切应力作用增加对小管间质细胞外基质(ECM)重塑的作用。方法:将细胞分为:正常对照组、甘露醇组、高糖组,以5dyn/cm2、10dyn/cm2的切应力作用于各组细胞,分别作用1h,3h,6h。RT-PCR法检测tPA及PAI-1mRNA的表达,免疫荧光标记检测细胞骨架肌动蛋白的表达。结果:正常对照组和甘露醇组tPA/PAI-1mRNA及细胞骨架肌动蛋白均有表达,高糖组tPA和细胞骨架肌动蛋白表达明显减弱,PAI-1表达明显增加;切应力呈大小和时间依赖性地下调tPAmRNA及细胞骨架肌动蛋白的表达,上调PAI-1mR-NA表达。结论:在DN早期,除高糖因素外,高滤过引起的切应力增加可诱导肾近端小管上皮细胞tPA/PAI-1mRNA表达失衡,可能是通过调节细胞骨架肌动蛋白的表达来实现的,导致ECM的降解减少,参与ECM的重塑。
Objective:To observe effects of shear stress on the expression of tissue plasminogen activator(tPA)mRNA and plasminogen activator inhibitor- 1 (PAl - 1 ) mRNA and cystoskeleton actin in high glucose cultured NRK52E cells (a kidney proximal tubular epithelial cell line of normal rat origin ), and investigate the mechanism of tubulointerstitial extracellular matrix (ECM) remodeling induced by increased shear stress in the early stage of diabetic nephropathy (DN). Methods:Cultured NRK52E cells were divided into three groups:control group, marmitol group, high glucose group, The different groups were expec, ed to shear stress of 5 dyn/cm^2 and 10 dyn/cm^2 for 1, 3 and 6 hour respectively, Semi - quantity RT - PCR were used to detect tPA/PAI - 1 mRNA expression. Immunofluoresence was used to detect the expression of cytoskeleton actin. Results: In cultured NRK52E cells without shear stress, there was the expression of tPA/PAI - 1 mRNA and cytoskeleton actin between control group and mannitol group. Compared with control group, the expression of tPA mRNA and cytoskeleton actin was significantly decreased and PAl - 1 mRNA expression was significantly increased in high glucose group. Shear stress has down - regulated the expression of tPA mRNA and cytoskeleton actin and has up - regulated PAl - 1 mRNA expression in a magnitude - and tine - dependent way. Conclusion: In the early stage of DN, besides high glucose, increased shear stress also induced the abnormal expression of tPA/PAI - 1 mRNA possibly by modulating the expression of cytoskeleton actin in the renal proximal tubular epithelial cells, and lead to an imbalance between ECM production and proteolysis of tubulointerstitial and involve in the remodeling of ECM.
出处
《中国中西医结合肾病杂志》
2008年第3期199-202,共4页
Chinese Journal of Integrated Traditional and Western Nephrology